An example of a conventional electrical connector 60 for connecting to a circuit board B by a surface mount reflow soldering technique is shown in FIG. 6 and comprises an insulating housing or body 61 having a bottom circuit board engaging face for mounting against a circuit board with an adjacent, rear face 60a of the housing upstanding from the circuit board B. A first and a second series of terminals are retained in the housing with respective lead portions 63 extending from the rear face 60a adjacent the board engaging face in closely spaced, parallel relation across the circuit board with the respective lead portions of the first series alternating with the respective lead portions of the second series and having transverse soldering portions at respective free ends thereof for connection to respective conductive paths 65 on the circuit board. The lead portions of the first series are of equal length and shorter than the lead portions of the second series so that the respective soldering portions of the first and second series are located in respective rows I and II with the row of soldering portions of the second series being further away from the housing than the row of soldering portions of the first series.
A disadvantage of the prior connector is that it is not easy to melt the solder joining the end of only a single soldering portion of a damaged terminal portion to the circuit board without disturbing other, adjacent, lead portions, even by using small ultrasonic or pulse heaters, as the lead portions of both series are at common above-board height and the pitch of the lead portions has narrowed in recent years in order to satisfy the inexorable demand for both increasing miniaturization and complexity.